Combination lock for security cabinets and the like



Sept. 5, 1967 H. c. MILLER ETAL 3,339,332

I COMBINATION LOCK FOR SECURITY CABINETS AND ,THE LIKE Filed'Dec. 15. 1964 5 Sheets-Sheet 1 iHg-i INVENTORS HARRY C. MILLER STEVEN HELESFAI lfiisowta Mame;

ATTORNEYS p 5, 1967 H. c. MILLER ETAL 3,339,382

COMBINATION LOCK FOR SECURITY CABINETS AND THE LIKE l I. HHUHHHHHHHHHIHHHIIHHHHHHHHHHHHHH 'Bg-QL 1 INVENTORS HARRY C.M|u.ea F

STEVEN HELEsFM ma i? 1110: wcc,

ATTORNEY? Sept- 1967 H. c. MILLER ETAL 3,339,332

COMBINATION LOCK FOR SECURITY CABINETS AND THE LIKE Filed Dec. 15, 1964 5 Sheets-Sheet 4 ave: limes: mQSMFM 6 mm ATTORNEYS p 1967 H. c. MILLER ETAL 3,

COMBINATION LOCK FOR SECURITY CABINETS AND THE LIKE sl em I 90 v 92 a m\ INg-IZ' INVENTORS Hmzav C. MILLER STEVEN HELEsFAI ATTORNEYS United States Patent 3,339,382 COMBINATION LOCK FOR SECURITY CABINETS AND THE LIKE Harry C. Miller and Steven Helesfai, Rochester, N.Y., as-

signors to Sargent & Greenleaf, Inc., Rochester, N.Y.,

a corporation of New York Filed Dec. 15, 1964, Ser. No. 418,424 14 Claims. (Cl. 70-23) The present invention relates in general to combination locks, and more particularly to combination padlocks of the concealed shackle type especially adapted to be used with security closures such as file cabinets, drawers and the like, wherein the lock housing has an opening to receive a hasp staple projecting from the security closure which is concealed from view by the lock housing and inaccessible when the padlock is engaged therewith.

Combination padlocks have been commonly used to lock file cabinets, drawers, and other security closures, but in most instances such padlocks have been of the exposed shackle variety having an exposed U-shaped shackle of hardened steel, one leg of which is slidably and rotatably retained in the padlock casing and the other leg of which is of shorter length and is adapted to be inserted through the opening or loop in the hasp staple after a slotted retaining bar, strap or plate has been fitted over the hasp staple, to retain the cabinet or closure in locked condition. In such structures, the exposed shackle is readily exposed to destruction or cutting by persons seeking unauthorized entry into the enclosure, and the lock components are usually readily subject to the corrosive action of climate and wear. More recently, padlocks specifically designed for such an application have been designed so that an opening is provided in the lock housing to receive the hasp staple therein, and a reciprocative bolt in the lock housing is projectable into and withdrawable from the opening to project through the hasp staple when the same is located in the housing opening and thereby interlock the staple therewith.

While some eiforts have been made to incorporate combination lock features into such padlocks, both of the exposed shackle and concealed shackle types, such attempts have had as their principal aim the provision of the coaxially associated, peripherally recessed tumbler wheels, the driving cam connected to a rotatable dial, and the lost-motion connection features of combination locks without incorporation of the high security features of specialized combination locks designed to prevent surreptitious detection of the combination by usual combination breaking techniques. Also, when combination key change features are incorporated in such padlocks, the opening through which the combination change key must 'be inserted when the combination is to be changed provides another possible avenue to surreptitious detection of the loci; combination or unauthorized manipulation of the loc An object of the present invention is the provision of a novel combination padlock having improved means for defeating or resisting surreptitious detection of the lock com-bination.

Another object of the present invention is the provision of a novel combination padlock of the concealed shackle type providing improved security features, and which is especially adapted for use with hasp shackles of security closures such as cabinets, drawers and the like.

Another object of the present invention is the provision of a combination padlock having peripherally gated tumbler wheels, a driving cam and a dial for rotating the same, wherein a fence lever coactive with the tumbler wheels and dFiViPg cam to open the lock is normally held in non-coactive position and is adjusted by impact into coactive position by special manipulation means independent of the dial in a selected relation to the dial manipulating sequence.

Another object of the present invention is the provision of a novel combination padlock having a dial for manipulating the changeable tumbler wheels and driving cam in accordance with the lock combination and an additional manually operable knob which must be manipulated in a special manner to bring the fence member into operative engagement with the tumblers for opening of the lock.

Another object of the present invention is the provision of a novel combination padlock of the concealed shackle type adapted to be received in a retaining bracket mounted on a security closure and be selectively interlocked therewith in a position preventing access to the combination change key access means of the lock and which is rendered removable from the mounting bracket only upon dialing of a selected combination in a special manner.

Another object of the present invention is the provision of a combination padlock of the concealed shackle type having novel means for conditioning the lock for changing of the lock combination and for normally protecting the combination changing mechanism against exposure to unauthorized operation.

Another object of the present invention is the provision of a combination padlock of the concealed shackle type having novel structure for resisting radiographic detection of the lock combination or forcible entry into the mechanism chamber of the lock housing by drilling.

Other objects, advantages, and capabilities of the present invention will become apparent from the following detail description, taken in conjunction withthe accompanying drawings illustrating a preferred embodiment of the invention.

In the drawings:

FIGURE 1 is a perspective view, from a position located forwardly and to the right side, of a combination padlock embodying the present invention, the same being illustrated in assembled position on a security closure in position to protect the closure against entry;

FIGURE 2 is a rear perspective view of the combination padlock;

FIGURE 3 is a vertical section view of the combination padlock, taken along the line 33 of FIGURE 1;

FIGURE 4 is a front elevation view of the interior mechanism subassembly and rear lock base, with the lock casing and dial and actuating knob carried by the casing removed therefrom;

FIGURE 5 is a side elevation view of the mechanism illustrated in FIGURE 4, viewed from the left-hand side of FIGURE 4;

FIGURE 6 is a side elevation view of the mechanism shown in FIGURE 4, viewed from the right-hand side of FIGURE 4;

FIGURE 7 is a bottom view of the mechanism shown in FIGURE 4;

FIGURE 8 is a front elevation view of the mechanism subassembly illustrated in FIGURE 4, showing the location of the components when the bolt is in retracted or unlocked position;

FIGURE 9 is a front elevation view similar to FIG- UR E 4, but illustrating the parts in a combination change position permitting removal of the lock from its associated mounting bracket and exposure of the key change opening to receipt of the combination changing key;

FIGURE 10 is an exploded perspective view of the principal Working components of the lock mechanism;

FIGURE 11 is a fragmentary front elevation view similar to FIGURE 4, illustrating a modified form of mechanism for accelerating the fence; and

FIGURE 12 is a section view taken along the line 12-12 of FIGURE 11.

Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures, the combination padlock of the present invention, generally designated by the reference character 12, includes a casing 13 in the form of a rearwardly opening shell-like body having substantially the shape of a rectangular solid providing a front wall 14, side walls 15, 16 and top and bottom walls 17, 18. A dial 19, including effectively integral dial and knob portions, is rotatably journalled in the front casing wall 14 with the knob portion projecting forwardly therefrom, the graduations on the dial portion 19a being preferably shielded from view by a conical shield formation 14a on the front wall covering all but a limited arcuate range aligned with a small sight opening 14a. In the preferred embodiment, this shield 14a is separately formed from the casing 13 and is rotatably journaled in the front wall 14 thereof, having a spring-like integral nose 14b on its periphery ooacting with detents in the casing wall 14 at quadrature locations to permit adjustment of the sight opening to face up, down or to either side. The dial '19 is especially constructed to provide radiant energy scattering metallic balls 21 therein, either loosely housed in an internal chamber in the dial or potted therein, and has a hardened steel disk 22 at the rear of the dial spanning substantially the maximum diameter thereof, to protect the lock against radiographic combination detecting techniques and drilling into the interior lock works chamber 23 of the casing. The lock works chamber is closed rearwardly by a base 24 formed of a thick plate member whose periphery conforms to and is slidably fitted into the rear opening to the works chamber 23 defined by the interior surfaces of the side, top and bottom walls of the casing 13. The base 24 is adapted to be supported against the front surface of the security closure to be protected, here shown as the drawer front 25 of a file cabinet 26 and includes a rearwardly offset formation 27 having a late-rally elongated opening 28 for reception of a hasp staple 29 from the file cabinet therethrough.

The lock 12 is removably supported in this mounted position in a bracket 30 fixed to the drawer front 25. To this end, the bracket 30 is provided with flanges 31 on the bottom and sides thereof terminating in inwardly projecting lips 32 to define a slide pocket to receive and hold U-shaped flange or tongue formation 33 on the casing 13 at the rearmost edges of side walls 15, 16 and bottom wall 18. An axially reciprocative locking pin 34 is supported in the base 24 and is biased by spring 35 to a retracted position wherein its rearmost end is flush with or forward of the rear surface of the base 24. The looking pin 34 is normally held in a projected position, by means to be later described, extending rearwardly of the base 24 into an interlocking socket or hole 36 in the bracket 30 to interlock the lock against withdrawal from the bracket 30.

A rearw-ardly opening cup-shaped shell 37 conforming substantially to the shape of the casing walls defining the lock works chamber 23 and formed of drill resistant hardened steel is nested in the chamber 23 against the casing walls to protect against drilling through the case to gain access to the interior mechanism. A circular opening 37a is provided in the front wall of the shell 37 in axial alignment with the dial 19 to permit coupling of the dial with the interior mechanism.

The basic components of the combination padlock forming the operative lock works are carried by the base 24 so as to facilitate their removal from and insertion into the chamber 23 of the lock casing 13. To this end, the base 24 has an integral, forwardly projecting tumbler mounting post 38 aligned axially with the axis of rotation of the dial 19. A bolt plate 3 9 is disposed immediately forwardly of the base 24 for vertical reciprocation against the forwardly facing surface of the base, and includes an elongated slot 40 through which the tumbler post 38 projects and which accommodates vertical reciprocative movement of the bolt 39 relative to the base. The bolt plate 39 also includes an integral, cylindrical bolt 41 slidably receivable into a generally conforming opening 42 in a forwardly projecting block portion 43 of the base 24, which block portion also includes a rearward-1y opening recess 44 aligned with the opening 28 in the base 24 to receive the forwardmost portion of the hasp staple 29.

As will be observed from FIGURE 3, the bolt 41 in projected position extends entirely through the opening in the hasp staple 29 and thereby interlocks the lock with the hasp staple.

Arranged in succession on the tumbler post 38 progressing forwardly from the bolt plate 39 are a lever carrier turntable 45 having a central opening therein conforming to the cross section of the tumbler post 38 to rotatably journal the turntable 45 thereon, a spiral spring 46, and changeable tumbler wheels 47, 48 and 49, between each of which are provided the usual washers 51 and rotatable flies 52. The tumbler wheels 47, 48 and 49 are of the usual changeable type, having an inner hub portion 53 freely rotatable on the tumbler post 38 and an outer rim portion 54 releasably interlocked with the hub 53 against relative rotation by rim locking means, which may be of conventional construction, including a combination change cam or rotatable member having an opening therein for receiving a combination change key insertable simultaneously through the combination change cam opening of each of the tumblers when the tumblers occupy selected angular positions to effect release of the hub 53 from the rims 54. An example of such combination change tumbler wheels is disclosed in earlier US. Patent No. 1,484,692, granted Feb. 26, 1924, to E. R. Weber, although it will be understood that other changeable tumbler wheel construction may be employed. Each of the tumbler wheels 47, 48 and 49 and the driving cam 50, which is separate from the tumbler post 38 but located against the end thereof, has a peripheral gate or recess 47a, 48a, 49a and 50a, at one angular position thereon, and each of the tumbler wheels has the usual lost-motion connecting means between that tumbler and the fly between that tumbler and the next successive tumbler progressing toward the driving cam, while the driving cam and the tumbler wheels 48 and 49 have drive pins, one of which is illustrated at 55 in FIGURE 10, by which rotation is successively imparted to the tumbler wheels 49, 48 and 47 upon rotation of the driving cam 50 alternately in clockwise and counterclockwise directions through selected numbers of complete revolutions in the conventional manner for combination locks. The turntable 45, tumbler wheels 4749, and associated components assembled in stacked relation on the tumbler post 38 are restrained in freely rotatable relation thereon by the usual split ring or other restraining means fitted into a circumferential groove adjacent the forwardmost end of post 38.

The lever carrier turntable 45 has fixed thereto generally above the tumbler wheel periphery a fence lever mounting bracket 56 having a yoke portion indicated at 57 in FIGURES 4 and 5, within which is pivotally supported a fence lever 58 having a pair of oppositely projecting ears or trunnions 59 extending into openings in the yoke portion 57 of the bracket 56 at one end of the lever 58 and having an inwardly curved nose 60 at the free end thereof adapted to be projected into the peripheral gates 47a-50a of the tumbler wheels 47-49 and driving cam 50. When the turntable 45 occupies the position illustrated in FIGURE 4, the fence lever 58 is held in a retracted position withdrawn from operative relation to the tumbler wheels and driving cam by means of a spring 61 connected between the fence lever 58 and the mounting bracket 56 and disposed in an overcenter relation relative to the pivot axis of the fence lever 58 to maintain the fence lever withdrawn into abutment with the adjacent side wall of the shell 37 in the lock casing 13.

The driving cam 50 has a cylindrical stub 50b projecting from the rear face thereof to fit into a central bore in the tumbler post 38 and is releasably intercoupled with the dial 19 to be driven thereby by means of a pair of diametrically opposite eccentric bosses 62 projecting forwardly of a cylindrical, forwardly projecting pedestal portion 63 on the driving cam conforming to and rotatable in the opening 37a in shell 37, which eccentric bosses 62 fit into corresponding eccentric sockets 64 opening through the rear face of the steel plate 22 fixed to the rear surface of the dial 19. Thus any rotation of the dial 19 will be transmitted directly to the driving cam 50 to rotate the driving cam 50 in a corresponding manner.

It will be appreciated that in conventional combination locks, the fence lever is allowed to drop under the influence of gravity to a position engaging the fence thereon with the peripheries of the tumbler wheels whenever the peripheral gate of the driving cam is aligned with the fence lever nose. This feature permits manipulation of the look by skilled persons in such a manner that the locations of the tumbler wheel gates and thus the lock combination, can be surreptitiously detected. The conditions obtaining in such conventional .locks which enable surreptitious entry in this manner are eliminated in the present invention by the over-center spring 61 which restrains the fence lever 58 in the withdrawn position illustrated in FIGURE 4, and thus out of contact with the tumbler wheels and driving cam, even when the gates 47a50a of the latter are properly aligned to receive the fence lever nose 60, requiring special means to effect movement of the fence lever into operative engagement with the tumbler wheels and driving cams.

In order to effect movement of the fence lever nose toward the tumbler wheel and driving cam peripheries, a vertically reciprocative accelerator slide 65, shown particularly in FIGURES 4, 8, 9 and 10, is slidably supported against the base 24 for vertical reciprocative movement in the upper left-hand 16011161 region, alongside part of the bolt plate, as viewed in FIGURES 4, 8 and 9. The accelerator slide 65 is guided along a vertical axis by rearwardly bent tabs 66, 66a tracking in guide grooves 67, 67a in the base 24 and is resiliently biased downwardly by a coil spring 68. The slide 65 has a specially shaped central opening 69 having a bent horizontal shoulder tab or surface 70 bounded on the left by an upward excursion 69a of the opening 69. The lower end portion of the accelerator slide 65 is of forked or swallowtail configuration to provide a pair of upwardly converging inclined surfaces 71 and 71a, and an intermediate inclined surface 72 is provided above and inwardly of the surface 71a relative to the center of the lock. The slide 65 is actuated by an externally accessible slide actuator knob 73 journalled in and projecting forwardly of the front wall of the casing, which i coupled in an axially releasable manner to the forward end of a shaft 74 to transmit rotation therebetween by coactive flats on the members. The shaft 74 has a non-circular rear end 74a, here shown as semicircular, projecting through the opening 69 of slide 65 on which a cam 75 is fitted to actuate the slide 65. The cam 75, as shown in FIGURES 810, has a circular periphery extending over almost threequadrants and a right angular interruption extending to the center over slightly more than the fourth quadrant bounded by an abrupt, substantially radial shoulder 75a and a shoulder 75b in parallel spaced relation to a radius of the cam at approximately right angles to the shoulder 75a joining the circular cam periphery by a smooth curve. The cam 75 and shaft 74 normally occupy the position shown in FIGURE 8, wherein the shoulder 75b of the cam is substantially horizontal and engages the under surface of the horizontal shoulder tab 70 of slide 65 to hold the slide against the force of spring 68 in the position shown. In this position, the inclined surface 71 of slide 65 lightly engages a rearwardly projecting ear 76 on the fence lever 58, which ear projects into a guide groove 77 in the base 24 and normally lies in the arcuat excursion 77a thereof enscribed about the pivot axis of the fence lever 58 as its center when the latter is in withdrawn or inactive position.

The actuator slide 65 is designed to be elevated by rotation of the knob 73, shaft 74 and cam 75 in a counterclockwise direction, as viewed in FIGURES 8 and 9, through 360 from the FIGURE 8 position, thereby elevating the actuator slide 65 against the force of spring 68, as shown in FIGURE 9, as the horizontal shoulder tab rides up on the circular periphery of cam 75. When the abrupt shoulder a of the cam 75 passes from under the shoulder tab 70, the slide 75 is suddenly driven downwardly by the compressed spring 68 and strikes the ear 76 with sufficient impact force to propel or kick the fence lever 58 about its pivot axis through a sufficient arc to shift the spring 61 over center with respect to the lever axis and draw the nose 60 of the fence lever into the tumbler wheel and driving cam gates 47a-50a if the latter are properly aligned to receive the fence lever nose. If the tumbler wheel and driving cam gates are not properly aligned to receive the fence lever nose 60, the nose 60 will engage the periphery of the driving cam 50 or of at least one of the tumbler wheels 47-49 before the spring 61 has been shifted through the pivot axis of the fence lever, thus maintaining the spring 61 above the fence lever pivot axis and causing immediate withdrawal of the fence lever 58 to the spaced inactive position shown in FIGURE 4.

If the nose 60 of the fence lever is received in aligned tumbler wheel and driving cam gates, the ear 76 of the fence lever reaches an inner or active position aligned with the descending arcuate portion 77b of groove 77, which permits the dial 19 to be then rotated in a counterclockwise direction, with reference to FIGURE 8, whereby the driving cam 50 draws the fence lever 58 now intercoupled therewith and the turntable 45 downwardly to the position shown in FIGURE 8. During this downward movement, the top shoulder 45a on the turntable 45 is shifted in a counterclockwise direction and from under the enlargement 39a of .the bolt plate 39 and the ear 76 on the fence lever 58 engages lateral projection 39b of the bolt plate 39 and forces the bolt plate and bolt down to the unlocked position shown in FIGURE 8. Upon reverse rotation of the dial 19 and driving cam 50 in a clockwise direction, the turntable 45 is similarly rotated by engagement of the fence lever nose 60 with the trailing or lower side of the driving cam gate 50a until the fence lever car 76 strikes the inclined surface 71a of the slide 65, which cams the fence lever outwardly through the arcuate extension of groove 77 to the withdrawn or inactive position. During this return or clockwise move ment of the turntable 45, the top shoulder 45a engages the downwardly facing curved surface of the projection 39a of 'bolt plate 39 and forces the bolt plate upwardly to locked position of FIGURE 4. It will be noted that in all positions of the turntable 45 at and between the aforementioned locked and unlocked positions, the arcuate tail portion 45b of the turntable laps forwardly over the head of locking pin 34, maintaining the latter in the projected position shown in FIGURE 4 interlocking the lock casing with the bracket 30. To assist in properly locating the turntable 45 at the locked and unlocked angular positions, spring check balls 78 are provided in the base 24 and project into apertures or sockets in the turntable at these positions.

When it is desired .to change the lock combination, the current combination of the lock is dialed to align the tumbler wheel and driving cam gates with the fence lever nose 60, and the auxiliary knob 73 is rotated counterclockwise through 540 rather than 360. This causes the actuator slide 65 to be elevated and dropped during the first 360 rotation of the knob 73 in the same manner as when unlocking the lock, whereupon the fence lever car 76 is kicked by the slide 65 and the fence lever nose 60 is inserted in the tumbler wheel and driving cam gates 47a50'a. During the succeeding 180 rotation of the knob 73 and cam 75, the slide 65 is again elevated and held in elevated position, raising the forked portion of the slide adjacent inclined surface 71a above the groove 77 and clearing the upper portion 770 of the groove for movement of the fence lever ear 76 therethrough. The dial 19 is then rotated in a clockwise direction to align the zero mark on the dial with the combination change index on the lock casing, which, through interaction of the fence lever nose with the trailing side of the driving cam gate, rotates the turntable 45 clockwise until the fence lever ear 76 strikes the ramp 77d in the groove 77. The ramp 77d cams the fence lever outwardly into the extension 772 of groove 77. Apertures or sockets are also provided in the turntable 45 to register with and receive the spring check balls 78 at this turntable position. In this combination change position of the turntable 45, the tail position 45b thereof is shifted to a position aligning the forwardly off-set tip thereof with the locking pin 34 and allowing the pin to be withdrawn by its spring 35 from the interlocking hole 36 in mounting bracket 30, whereupon the lock can be manually removed from the bracket 30 and the back thereof exposed. A combination change key is then inserted in the change key opening 79 in the base 24 and into the openings in the combination changing cams of the tumbler wheels 4749, which are now aligned with the change key opening 79, and the key is rotated to unlock the tumbler rims from their hubs. The new combination is then dialed on the changing index in the usual manner, adjusting the tumbler hubs to their new angular positions, the change key is withdrawn, the auxiliary knob 73 is turned counterclockwise 360 to bring the inclined surface 72 into contact with fence lever car 76 and propel the fence lever back to the active position disposing the nose 60 in the gates 47a50a and again elevating the side 65, the lock casing is reassembled with bracket 30, and the dial 19 is then turned to align the zero dial mark with the dialing index on the lock casing. During this last-mentioned movement, the fence lever ear 76 rides up the ramp 77d and into the arcuate extension 77a of groove 77 to return the fence lever to the retracted or inactive position of FIGURE 4. The auxiliary knob 73 is, of course, then returned to the normal position disposing the cam 75 in the FIGURE 4 position. The turntable 45 has an opening 450 therein positioned to register with the change key opening 79 in the base 24 only when the turntable 45 is in the key change position, and the bolt plate 39 has a similar Opening 39b which is aligned with opening 79 only when the bolt plate is in locked position. Thus the change key opening 79 is cleared to permit entry of the change key into the cams of the tumbler wheels only when the casing 13 is removed from the bracket 30, the turntable 45 is in change position, and the bolt plate 39 is in locked position.

A scrambler 80 is provided on the bolt plate 39 to upset the tumblers following opening and reclosing of the lock, including a body portion 81 slidably supported in a side of the enlarged portion of bolt plate 39 having a spring catch 82 projecting therefrom, and a return spring 83 normally drawing the scrambler to its uppermost position. When the bolt plate 39 is drawn downwardly during unlocking of the lock, the catch 82 interlocks with the peripheral serrations on at least two of the tumbler peripheries. As the bolt plate 39 rises upon return movement of the turntable 45 and bolt plate 39 to locked position, the spring 83 is tensioned as the catch 82 and body portion cannot move upwardly with the bolt plate until the fence lever nose 60 is withdrawn from the tumbler wheel and driving cam gates 47a-50a. Upon withdrawal of the fence lever nose from the tumbler gates, the spring 83 immediately retracts the spring catch 82, spinning the tumbler wheels engaged thereby and disarranging the tumblers so that they no longer correspond to the combination.

It will be noted that the right-hand forked or swallowtail portion of slide 65 immediately adjacent inclined surface 71a serves, when the slide 65 has been lifted and dropped by cam 75 to kick in fence lever 58 upon rotation of auxiliary knob 73, to keep the operator from then turning the dial 19 in a clockwise direction as viewed from the front. Since this right-hand forked portion of slide 65 then lies across the upper portion 770 of groove 77, the inclined surface 71a would intercept the fence lever car 76, upon attempted clockwise rotation of the dial 19, thus preventing such rotation of the dial 19 when the auxiliary knob 73 has been rotated only 360 as would shift the turntable 45 to combination changing position.

Also, the design of the upper arcuate excursion in the guide groove 77 wherein the larger radius side thereof nearest the arcuate excursion 77a prevents return of the turntable 45 and fence lever 58 to the normal locked position without first actuating the auxiliary knob 76 to propel the fence lever to the active inner position, provides failsafe protection against inadvertent locking without having set the intended combination. This insures that deliberate special action must be taken to effect return of the turntable and fence lever to the normal locked condition.

It will be appreciated that by the construction herein- .above described, a combination padlock of the concealed shackle type is provided wherein the fence lever is normally restrained by an overcenter spring in an inactive position spaced out of contact with the tumbler wheels and drive cam, and which requires special manipulation of the knob 73 when the tumbler and driving cam gates have all been aligned properly to receive the fence lever nose to effect projection of the fence lever to the active position permitting rotation of the turntable 45 by subsequent rotation of the dial 19 and driving cam 50. Further, the lock is always maintained in interlocked condition in the supporting bracket 30 shielding the combination change key opening in covered relation preventing access thereto, until the dial 19 and knob 73 are manipulated in a special manner. Such mechanism therefore provides a combination padlock which is especially suitable for protecting security cabinets and like receptacles under circumstances requiring high security requirements more stringent than those requiring mere conventional combination locks.

A somewhat simplified version of means for accelerating the fence from the withdrawn or inactive position to the lowered operative position interfitting the fence lever nose in the tumbler and driving cam gate is illustrated in FIGURES l1 and 12, wherein the lock components like those in the previously described embodiment are designated by the same reference characters as before. In this modification, the accelerator slide 65, spring 68, knob 73, and shaft 74 and cam 75 are eliminated, and a simple spring is provided, having an anchored end 90a fixed in the block portion 43 of the base 24 and a generally inverted U-shaped formation at its opposite end above the fence lever 58 defining a curved bearing foot 90b near the end of the spring 90 and a second bearing portion 900 spaced slightly therefrom. The spring 90 is positioned and controlled by an axially moveable push button 91 substituted for the knob 73, shaft 74 and cam 75. The push button 91 is resiliently biased outwardly by a spring 92 and includes cam surface formations 91a which may be formed of screw threads or a projecting annular rib of triangular profile defining a crest 91a and a pair of axially spaced troughs 91a" and 91a'. It will be appreciated that, if desired, cam surface formations of similar profile may be provided on only the upwardly facing portion of the push button. The bight portion 90d of the spring 90 normally engages in the innermost trough 91a", locating the free portion of the spring 90 at a position such that the hearing foot 901) lightly bears on the fence lever 58. After the proper combination has been dialed to unlock the lock and the gates of the tumbler wheels 47-49 and of the driving cam 50 are all aligned to receive the fence lever nose 60, the push button 90 is then pushed axially inwardly against the force of spring 92. During this movement of the push button 91, the free portion of accelerator spring 90 is loaded as the spring portion engaging the cam surface formation 91a is first caused to ride up the incline to the crest 91a and is then released to ride downwardly into the outermost trough 91a'. This action is sufficiently rapid so that the release or downward movement of the loaded spring transfers enough impact force to the fence lever 58 when the foot 90b contacts the same to shift the fence lever 58 and spring 61 over center and drive the fence lever nose 60 radially inwardly into the tumbler wheel and driving cam gates. The dial is then rotated in a counterclockwise direction as viewed in FIGURE 11 in the manner described in the preceding embodiment to rotate the fence lever and turntable and withdraw the bolt to the unlocked position. Similarly, when the combination is dialed to align the tumbler wheel and driving camsgates with the fence lever nose and the push button 91 is activated to kick in the fence lever, the dial can be rotated in a clockwise direction as viewed in FIGURE 11 to align the zero mark with the combination change index on the lock casing, which, as in the preceding embodiment rotates the turntable to a position releasing the locking pin 34 to be withdrawn by its spring 35 from the interlocking hole in the mounting bracket 30 and aligning the holes in the combinating changing cams in the tumbler wheels with the combination change key hole 79 in the base 24. Upon withdrawal of the look from the bracket 30, the hole 79 is exposed for insertion of the change key. Suitable inclined surfaces on the track in which the fence lever ear 76 runs kick the fence lever out at the combination change position of the tumbler wheels and driving cam, freeing the driving cam for rotation with the dial to adjust the tumbler hubs to the new combination positions. At this angular position of the tumbler wheels and driving cam, the fence lever is engaged by the second bearing portion 900 of the spring 90. Thus, when the tumbler hubs have been reset for the new combination, the push button 91 is again pressed inwardly, loading and releasing the spring 90 to effect impact of the bearing portion 900 on the fence lever and kick the fence lever nose into the gates, whereupon the dial can be rotated counterclockwise to return the zero mark into .alignment with the normal index and thereby return the fence lever and tumbler wheels and driving cam to the normal FIGURE 4 position.

If desired, still other modifications can be made wherein the dial may be rotated in a special manner to load and release the accelerator means or spring to kick the fence lever into the tumbler wheel and driving cam gates, as by providing a cam projection or pin on the driving cam to contact the spring or some activating member coupled to the accelerator means during rotation of the driving cam to the fence receiving position following adjustment of the tumbler wheels.

While but two preferred embodiments of the present invention have been particularly shown and described, it is apparent that various modifications may be made therein within the spirit and scope of the invention, and it is desired, therefore, that only such limitations be placed on the invention as are imposed by the prior art and set forth in the appended claims.

We claim:

1. In a combination lock having a plurality of peripherally gated tumbler wheels loosely joumalled for rotation about a common axis, a peripherally gated driving cam rotatable about the common axis, a lost motion driving connection between said driving cam and tumbler wheels, a rotatable dial for rotating said driving cam to angularly adjust said tumbler wheels to dispose the peripheral gates in alignment, and reciprocative bolt means to be selectively shifted to locked and unlocked positions; the improvement comprising fence means for selectively shifting said bolt means between said locked and unlocked positions responsive to rotation of the driving cam including a fence lever having a nose to be received in said peripheral gates when said tumbler wheels and driving cam occupy selected angular positions, means supporting said fence lever for arcuate translatory movement circumferentially of the tumbler wheels and for pivotal movement about a pivot axis from an inactive position spacing said nose out of operative engagement with the tumbler wheel and driving cam peripheries to an active position locating said nose in said gates, overcenter spring means normally occupying a position holding said fence lever at said inactive position, and accelerator means including a rotatable cam operative from externally of the lock independently of the dial and a resiliently biased member within the lock movable responsive to said cam for exerting an impact force on said fence lever to propel the fence lever to said active position when said peripheral gates are aligned to receive said nose therein, said overcenter spring means returning said fence lever to said inactive position when said gates are not aligned with said nose and assuming a position holding said fence lever in said active position when said nose is projected into said gates.

2. In a combination lock having a plurality of peripherally gated tumbler wheels loosely journalled for rotation about a common axis, a peripherally gated driving cam rotatable about the common axis, a lost motion driving connection between said driving cam and tumbler wheels, a rotatable dial for rotating said driving cam to angularly adjust said tumbler wheels to dispose the peripheral gates in alignment, and reciprocative bolt means to be selectively shifted to locked and unlocked positions; the improvement comprising fence means for selectively shifting said bolt means between said locked and unlocked positions responsive to rotation of the driving cam including a fence lever having a nose to be received in said peripheral gates when said tumbler wheels and driving cam occupy selected angular positions, a rotatable carrier supporting said fence lever for arcuate translatory movement about said common axis for pivotal movement about a pivot axis from an inactive position spacing said nose out of operative engagement with the tumbler wheel and driving cam peripheries to an active position locating said nose in said gates, overcenter spring means normally occupying a position holding said fence lever at said inactive position, accelerator means including a rotatable cam operative from externally of the lock independently of the dial and a resiliently biased slide member adjacent said fence lever and movable responsive to said cam for exerting an impact force on said fence lever to propel the fence lever to said active position when said peripheral gates are aligned to receive said nose therein, said overcenter spring means returning said fence lever to said inactive position when said gates are not aligned with said nose and assuming a position holding said fence lever in said active position when said nose is projected into said gates, and means on said carrier for driving said bolt means between said locked and unlocked positions responsive to arcuate translation of said fence lever with said driving cam when said fence lever is in said active position.

3. In a combination lock, the combination defined in claim 2, including a lock casing wall located adjacent said carrier, said fence lever having an ear located eccentrically of its pivot axis projecting toward said wall, and said wall having a groove therein continuously receiving said fence lever ear therein including an arcuate portion generally concentric with said common axis extending along the path traversed by said ear when the fence lever occupies said active position and the carrier is rotated about said common axis from locking to unlocking position and including an arcuate excursion projecting away from said common axis along the path traversed by said ear when said fence lever is rotated about its pivot axis from active to inactive position when said carrier is in fully locked position, said groove excursion having walls coacting with said ear to restrain movement of said carrier and fence lever about said common axis when said fence lever occupies said inactive position.

4. In a combination lock, the combination defined in claim 3, wherein said lock includes a lock casing having a combination change key opening in a wall thereof, said groove in said casing wall including an extension generally concentric with said common axis extending as a continuation of said arcuate portion in a direction to accommodate said ear during rotation of said carrier in a direction opposite movement thereof from locked to unlocked position with said fence lever in active position, said continuation terminating in an arcuate excursion like said first-mentioned arcuate excursion at -a selected combination change angular position of said carrier, said lock including an interlock member normally locking said lock in mounted relation on a surface covering said change key opening, and said carrier including a portion normally maintaining said interlock member in locking position and located when said carrier reaches said combination change position to release said interlock member to permit removal of the lock from said surface, said carrier having a change key opening normally out of registry with the change key opening in said casing wall and registering therewith only at said combination change position, said accelerator means normally closing said groove extension against entry of said fence lever ear therein and being adjustable to expose said extension to receive said ear.

5. In a combination lock having a plurality of peripherally gated tumbler wheels loosely journalled for rotation about a common axis, a peripherally gated driving cam rotatable about the common axis, a lost motion driving connection between said driving cam and tumbler wheels, a rota-table dial for rotating said driving cam to angularly adjust said tumbler wheels to dispose the peripheral gates in alignment, and reciprocative bolt means to be selectively shifted to locked and unlocked positions; the improvement comprising fence means for selectively shifting said bolt means between said locked and unlocked positions responsive to rotation of the driving cam including a fence lever having a nose to be received in said peripheral gates when said tumbler wheels and driving cam occupy selected angular positions, a rotatable carrier supporting said fence lever for arcuate translatory movement about said common axis and for pivotal movement about a pivot axis from an inactive position spacing said nose out of operative engagement with the tumbler wheel and driving cam peripheries to an active position locating said nose in said gates, overcenter spring means normally occupying a position holding said fence lever at said inactive position, accelerator means operative from externally of the lock independently of the dial for exerting an impact force on said fence lever to propel the fence lever to said active position when said peripheral gates are aligned to receive said nose therein, said overcenter spring means returning said fence lever to said inactive position when said gates are not aligned with said nose and assuming a position holding said fence lever in said active position when said nose is projected into said gates, and means on said carrier for driving said bolt means between said locked and unlocked positions responsive to arcuate translation of said fence lever with said driving cam when said fence lever is in said active position.

6. A concealed shackle combination padlock of the type adapted to envelop a hasp staple when in locked relation therewith comprising a lock casing providing a rearwardly opening tumbler chamber and having a removable rear base for closing said chamber, said base having a tubular post thereon, a plurality of peripherally gated tumbler wheels loosely journalled for rotation about a common axis on said tubular post, a peripherally gated driving cam rotatable about the common axis, a lost motion driving connection between said driving cam and tumbler wheels, a rotatable dial accessible forwardly of said casing for rotating said driving cam to angularly adjust said tumbler wheels to dispose the peripheral gates in alignment, said base having a rearwardly opening recess for receiving and enveloping a hasp staple, a reciprocative bolt plate slidably intercoupled with said post to be selectively shifted to locked and unlocked positions, said bolt plate having an integral bolt to be projected into said hasp staple opening into locked relation with the staple and withdrawn therefrom at said locked and unlocked positions respectively, fence means for selectively shifting said bolt plate between said locked and unlocked positions responsive to rotation of the driving cam including a fence lever having a nose to be received in said peripheral gates when said tumbler wheels and driving cam occupy selected angular positions, means supporting said fence lever for translatory movement in a generally tangential direction alongside the tumbler wheels and for pivotal movement about a pivot axis from an inactive position spacing said nose out of operative engagement with the tumbler wheel and driving cam peripheries to an active position locating said nose in said gates, overcenter spring means normally occupying a position holding said fence lever at said inactive position, accelerator means operative by a knob located externally of the lock and independently of the dial for exerting an impact force on said fence lever to propel the fence lever to said active position when said peripheral gates are aligned to receive said nose therein, said overcenter spring means returning said fence lever to said inactive position when said gates are not aligned with said nose and assuming a position holding said fence lever in said active position when said nose is projected into said gates, and means on said fence supporting means engageable with said bolt plate for driving said bolt plate between said locked and unlocked positions responsive to arcuate translation of said fence lever with said driving cam when said fence lever is in said active position.

7. A concealed shackle combination padlock of the type adapted to envelop a hasp staple when in locked relation therewith comprising a lock casing providing a rearwardly opening tumbler chamber and having a removable rear base for closing said chamber, said base having a tubular post thereon, a plurality of peripherally gated tumbler wheels loosely journalled for rotation about a common axis on said tubular post, a peripherally gated driving cam rotatable about the common axis, a lost motion driving connection between said driving cam and tumbler wheels, a rotatable dial accessible forwardly of said casing for rotating said driving cam to angularly adjust said tumbler wheels to dispose the peripheral gates in alignment, said base having a rearwardly opening recess for receiving and enveloping a hasp staple, a reciprocative bolt plate slidably intercoupled with said post for sliding movement between said base and tumbler wheels to be selectively shifted to locked and unlocked positions, said bolt plate having an integral bolt to be projected into said hasp staple opening to locked relation with the staple and withdrawn therefrom at said locked and unlocked positions respectively, fence means for selectively shifting said bolt plate between said locked and unlocked positions responsive to rotation of the driving cam including a fence lever having a nose to be received in said peripheral gates when said tumbler wheels and driving cam occupy selected angular positions, a rotatable carrier supporting said fence lever for arcuate translatory movement about said common axis and for pivotal movement about a pivot axis from an inactive position spacing said nose out of operative engagement with the tumbler wheel and driving cam peripheries to an active position locating said nose in said gates, overcenter spring means normally occupying a position holding said fence lever at said inactive position, accelerator means operative by a knob located externally of the lock and independently of the dial for exerting an im- 13 pact force on said fence lever to propel the fence lever to said active position when said peripheral gates are aligned to receive said nose therein, said overcenter spring means returning said fence lever to said inactive position when said gates are not aligned with said nose and assuming a position holding said fence lever in said active position when said nose is projected into said gates, and means on said carrier engageable with said bolt plate for driving said bolt plate between said locked and unlocked positions responsive to arcuate translation of said fence lever with said driving cam when said fence lever is in said active position.

8. In a combination lock as defined in claim 7, said fence lever having an ear located eccentrically of its pivot axis projecting toward said base, and said base having a groove therein continuously receiving said fence lever ear therein and restricting the location thereof including an arcuate portion generally con-centric with said common axis extending along the path traversed by said car when the fence lever occupies said active position and the carrier is rotated about said common axis from locking to unlocking position and including an arcuate excursion projecting away from said common axis along the path traversed by said ear when said fence lever is rotated about its pivot axis from active to inactive position when said carrier is in fully locked position, said groove excursion having walls coacting with said ear to restrain movement of said carrier and fence lever about said common axis when said fence lever occupies said inactive position.

9. In a combination lock, the combination defined in claim 8, said base having a combination change key opening therein, said groove including an extension to accommodate movement of said fence lever ear therein in active position upon rotation of said driving cam and carrier from locked position to a combination change position in a direction opposite the direction of rotation thereof from locked to unlocked position, said carrier having portions continuously covering said change key opening at and between locked and unlocked positions of said carrier and having an opening registering with said change key opening at said combination change position.

10. In a combination lock, the combination defined in claim 9, wherein said lock casing includes coplanar flange members projecting oppositely therefrom adjacent said base adapted to be slidably interfitted and held in a mounting bracket by movement of the casing along a plane paralleling said base with said bracket in covering relation to said change key opening, an interlock pin axially movable in said base from a projected to a retracted position, spring means biasing said pin to said retracted position, and said carrier including a portion normally maintaining said interlock pin in projected position to interlock in an accommodating aperture in said bracket and located when said carrier reaches said combination change position to release said interlock pin to said retracted position to permit removal of the lock from said bracket.

11. A padlock assembly for security cabinets and the like having a flat cabinet drawer front, the assembly including a concealed shackle combination padlock of the type adapted to envelop a hasp staple when in locked relation therewith comprising a lock casing providing a rearwardly opening tumbler chamber and covered by a base, said base having a flat rear surface, a plurality of peripherally gated tumbler wheels loosely journalled for rotation about a common axis in said casing, a peripherally gated driving cam rotatable about the common axis, a lost-motion driving connection between said driving cam and tumbler wheels, a rotatable dial accessible forwardly of said casing for rotating said driving cam to angularly adjust said tumbler wheels to dispose the peripheral gates in alignment, said base having a rearwardly opening recess for receiving and enveloping a hasp staple projecting from said cabinet, a reciprocative bolt plate casing to be selectively shifted to locked and unlocked positions, said bolt plate having an integral bolt to be projected into said hasp staple opening to locked relation with the staple and withdrawn therefrom at said locked and unlocked positions respectively, fence lever means to be intercoupled with said driving cam when said tumbler wheel gates are aligned to receive said fence lever means for selectively shifting said bolt plate between said locked and unlocked positions responsive to rotation of the driving cam, said lock casing having rib-like flanges projecting oppositely parallel to said rear base surface on opposite sides thereof, a mounting bracket adapted to be fastened to said drawer front having flanges and retaining lips defining a pocket conforming substantially to the profile of said rib-like flanges to slidably receive the latter and the adjoining portion of the lock casing therein upon relative movement in a plane paralleling said rear base surface and restrain the same against withdrawal in a direction perpendicular to said plane, said bracket having a pinreceiving opening therein, said base having a reciprocative pin therein biased to a retracted position and movable to a projected position in said pin-receiving opening interlocking said casing against withdrawal from said bracket, and means in said casing normally holding said pin in projected position and movable responsive to adjustment of said driving cam and fence lever to a selected position to release said pin to said retracted position.

12. In a padlock assembly, the combination defined in claim 11, wherein said fence lever means includes a carrier plate supported for rotation about said common axis, a fence lever pivoted on said carrier plate for arcuate movement into and out of said peripheral gates and for movement about said common axis with said carrier plate between locked and unlocked positions, said carrier plate having a portion continuously bearing against said pin to retain the pin in projected position when said carrier plate is at and between said locked and unlocked positions and having a portion registering with said pin at another selected angular position of said carrier plate accommodating movement of said pin to retracted position.

13. In a padlock assembly as defined in claim 12, said base and carrier plate each having a combination change key opening therein, the change key opening in said base being covered by said bracket when said lock casing is interlocked therein, and said change key openings being positioned to register with each other only when said carrier plate is disposed at said selected angular position.

14. A padlock assembly .for security cabinets and the like having a flat cabinet drawer front, the assembly including a concealed shackle combination padlock of the type adapted to envelop a hasp staple when in locked relation therewith comprising a lock casing providing a rearwardly opening tumbler chamber and covered by a base, said base having a flat rear surface, a plurality of peripherally gated tumbler wheels loosely journalled for rotation about a common axis in said casing, a peripherally gated driving cam rotatable about the common axis, a lost-motion driving connection between said driving cam and tumbler Wheels, a rotatable dial accessible forwardly of said casing for rotating said driving cam to angularly adjust said tumbler wheels to dispose the peripheral gates in alignment, said base having a rearwardly opening recess for receiving and enveloping a hasp staple projecting from said cabinet, a reciprocative bolt plate casing to be selectively shifted to locked and unlocked positions, said bolt plate having an integral bolt to be projected into said hasp staple opening to locked relation with the staple and withdrawn therefrom at said locked and unlocked positions respectively, fence lever means to be intercoupled with said driving cam when said tumbler wheel gates are aligned to receive said fence lever means for selectively shifting said bolt plate between said locked and unlocked positions responsive to rotation of the driving cam, said lock casing having a U-shaped flange bounding said base at the sides and bottom thereof, a mounting bracket 15 adapted to be fastened to said drawer front having flanges and retaining lips defining a pocket conforming substantially to the profile of said U-shaped flange to slidably receive the latter and the adjoining portion of the lock casing therein upon relative movement in a plane paralleling said rear base surface and restrain the same against withdrawal in a direction perpendicular to said plane, said bracket having a pin-receiving opening therein, said base having a reciprocative pin therein biased to a retracted position and movable to a projected position in said pinreceiving opening interlocking said casing against withdrawal from said bracket, and means in said casing normally holding said pin in projected position and movable responsive to adjustment of said driving cam and fence 16 lever to a selected position to release said pin to said retracted position.

References Cited UNITED STATES PATENTS 2,573,189 10/1951 Eiffert et a1 7023 2,625,032 1/1953 Eitfert et al 70314 X 2,792,703 5/1957 Murray 70333 X 2,970,217 1/1961 Enikeielf 70333 X 3,045,466 7/ 1962 Herlong 70-303 3,176,486 4/1965 Richardson 70303 X FOREIGN PATENTS 1,014,875 8/ 1957 Germany.

BOBBY R. GAY, Primary Examiner. 

1. IN A COMBINATION LOCK HAVING A PLURALITY OF PERIPHERALLY GATED TUMBLER WHEELS LOOSELY JOURNALLED FOR ROTATION ABOUT A COMMON AXIS, A PERIPHERALLY GATED DRIVING CAM ROTATABLE ABOUT THE COMMON AXIS, A LOST MOTION DRIVING CONNECTION BETWEEN SAID DRIVING CAM AND TUMBLER WHEELS, A ROTATABLE DIAL FOR ROTATING SAID DRIVING CAM TO ANGULARLY ADJUST SAID TUMBLER WHEELS TO DISPOSE THE PERIPHERAL GATES IN ALIGNMENT, AND RECIPROCATIVE BOLT MEANS TO BE SELECTIVELY SHIFTED TO LOCKED AND UNLOCKED POSITIONS; THE IMPROVEMENT COMPRISING FENCE MEANS FOR SELECTIVELY SHIFTING SAID BOLT MEANS BETWEEN SAID LOCKED AND UNLOCKED POSITIONS RESPONSIVE TO ROTATION OF THE DRIVING CAM INCLUDING A FENCE LEVER HAVING A NOSE TO BE RECEIVED IN SAID PERIPHERAL GATES WHEN SAID TUMBLER WHEELS AND DRIVING CAM OCCUPY SELECTED ANGULAR POSITIONS, MEANS SUPPORTING SAID FENCE LEVER FOR ARCUATE TRANSLATORY MOVEMENT CIRCUMFERENTIALLY OF THE TUMBLER WHEELS AND FOR PIVOTAL MOVEMENT ABOUT A PIVOT AXIS FROM AN INACTIVE POSITION SPACING SAID NOSE OUT OF OPERATIVE ENGAGEMENT WITH THE TUMBLER WHEEL AND DRIVING CAM PERIPHERIES TO AN ACTIVE POSITION LOCATING SAID NOSE IN SAID GATES, OVERCENTER SPRING MEANS NORMALLY OCCUPYING A POSITION HOLDING SAID FENCE LEVER AT SAID INACTIVE POSITION, AND ACCELERATOR MEANS INCLUDING A ROTATABLE CAM OPERATIVE FROM EXTERNALLY OF THE LOCK INDEPENDENTLY OF THE DIAL AND A RESILIENTLY BIASED MEMBER WITHIN THE LOCK MOVABLE RESPONSIVE TO SAID CAM FOR EXERTING AN IMPACT FORCE ON SAID FENCE LEVER TO PROPEL THE FENCE LEVER TO SAID ACTIVE POSITION WHEN SAID PERIPHERAL GATES ARE ALIGNED TO RECEIVE SAID NOSE THEREIN, SAID OVERCENTER SPRING MEANS RETURNING SAID FENCE LEVER TO SAID INACTIVE POSITION WHEN SAID GATES ARE NOT ALIGNED WITH SAID NOSE AND ASSUMING A POSITION HOLDING SAID FENCE LEVER IN SAID ACTIVE POSITION WHEN SAID NOSE IS PROJECTED INTO SAID GATES. 